Abstract: In the case of a system for controlling a motorcycle air bag with respect to the sitting position of a motorcycle occupant, a distance measuring device measures the distance of the motorcycle occupant with respect to the motorcycle, and an adaptation device controls a motorcycle air bag corresponding to this distance.

Abstract: A vehicle frame is described which has a step-through opening, particularly for a two-wheeler, for a vehicle having a resilient front wheel suspension, a steering device for a front wheel, a resilient rear wheel suspension for at least one rear wheel, at least one seat device for a driver and at least one protection device which extends in front of, over and behind the driver and is designed such that a laterally open cage is created for the driver which permits the stepping-through, and having an engine which is mounted essentially in front of the rear wheel and below the seat device.

Abstract: Aziridinocarboxylic acid esters of polyols are manufactured by trans-esterification of the corresponding esters of lower alcohols, using magnesium oxide or calcium oxide as the trans-esterification catalyst; this method gives a higher yield and a purer product.